How to Replace a Broken Roller Shutter Strap (Tape)

It happens suddenly: you pull the strap to raise your roller shutter, you hear a snap, and the shutter crashes down. Now you are left with a dark room and a limp piece of canvas tape in your hand.

Replacing the strap (often called the “tape” or “belt”) of a rolling shutter is a rite of passage for many homeowners, especially in Europe where these shutters are standard.

While it looks intimidating because you have to open the wall box, the mechanism inside is actually quite simple. You don’t need a professional, but you do need to be careful—shutters are heavy.

Here is the safe, step-by-step method to change the strap and get your light back.

Safety First: The Golden Rule

WARNING: Before you start, ensure the shutter is completely lowered. If the strap broke while the shutter was up, the heavy slats have likely already fallen. If they are stuck halfway, force them gently down until they rest on the windowsill. Never work on the mechanism with the shutter hanging; it could drop on your fingers.

What You Need

• New Shutter Strap: Buy a roll (usually 6 meters is standard for a window, 8+ meters for a door). Measure the width of your old one (usually 14mm, 18mm, or 22mm).
• Screwdriver: Flathead and Phillips.
• Scissors.
• A Screw or Nail: To secure the new strap (some systems use knots, others screws).
• A Helper: (Optional, but very helpful for holding the axle).

Step 1: Open the Top Box (The Shutter Housing)

The mechanism is hidden inside the box above the window.

1. Look for the screws on the panel cover (sometimes they are painted over).
2. Unscrew them and carefully pry off the cover.
3. Inside, you will see the axle (the metal or wood tube) and the old remains of the strap.

Step 2: Remove the Old Strap from the Top

1. Since the shutter is down, the axle should be bare.
2. Locate where the old strap is attached to the pulley (the wheel on one side of the axle).
3. Remove the old knot, screw, or clip.
4. Important: Pull the old strap out through the slot/guide in the wall.

Step 3: Prepare the Bottom Coiler (The Tricky Part)

Now, look at the bottom of the window frame where the strap winder (recoil box) lives.

1. Unscrew the winder from the wall and pull it out.
2. CAUTION: Inside this box is a spring under high tension.
3. Remove the old strap remains.
4. The Tension Trick: You need to “charge” the spring. Turn the wheel of the winder manually (against the resistance) until it is fully wound up.
5. Hold it tight! Don’t let go, or it will spin violently.
6. Once fully wound, thread the new strap through the brake (the metal clamp) and hook it onto the internal wheel (usually a slit or a button).
7. Slowly let the spring pull the new strap inside the winder until you have about 30cm (12 inches) left sticking out.
8. Screw the winder box back into the wall.

Step 4: Thread and Attach the Top

Now you have the new strap coming out of the bottom winder.

1. Feed the loose end of the strap up through the guide slot in the wall so it enters the top box.
2. Check for Twists: Make sure the strap is not twisted inside the wall.
3. Go up to the top box. Pull the strap up until it reaches the pulley on the axle.
4. Attach it: Secure the strap to the pulley using the same method as the old one (knot, screw, or slit).

Step 5: Winding the Strap (The Final Adjustment)

This is where logic gets confusing, so follow closely:

Currently, your shutter is down, but your strap is fully extended. You need to wind the strap onto the pulley so that when you pull it, it lifts the shutter.

1. Lift the shutter manually: Have your helper push the shutter slats up from the bottom (or rotate the axle by hand) until the shutter is all the way up (open).
2. While the shutter is being lifted, manually wind the loose strap around the pulley in the top box.
3. Keep winding until the slack is gone.
4. Once the shutter is up and the strap is wound tight around the pulley, let go gently. The weight of the shutter is now hanging on the strap.

Step 6: Close Up

Test the system. Pull the strap to lift and lower the shutter a few times.

• Does it move smoothly?
• Does the winder at the bottom collect the tape properly?

If it works, screw the top box cover back on.

Changing a roller shutter strap is a classic DIY job that looks harder than it is. The secret is simply understanding the spring mechanism at the bottom: wind the spring before attaching the tape.

You’ve just saved yourself a service call fee and learned exactly how your windows work.

Pro Tip: If your strap breaks often, check the “guide” (the slot where the tape enters the wall). If it’s rusty or sharp, it’s cutting your tape. Sand it smooth or replace the guide roller.

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